Fusarium Tri8 encodes a trichothecene C-3 esterase

Appl Environ Microbiol. 2002 Jun;68(6):2959-64. doi: 10.1128/AEM.68.6.2959-2964.2002.

Abstract

Mutant strains of Fusarium graminearum Z3639 produced by disruption of Tri8 were altered in their ability to biosynthesize 15-acetyldeoxynivalenol and instead accumulated 3,15-diacetyldeoxynivalenol, 7,8-dihydroxycalonectrin, and calonectrin. Fusarium sporotrichioides NRRL3299 Tri8 mutant strains accumulated 3-acetyl T-2 toxin, 3-acetyl neosolaniol, and 3,4,15-triacetoxyscirpenol rather than T-2 toxin, neosolaniol, and 4,15-diacetoxyscirpenol. The accumulation of these C-3-acetylated compounds suggests that Tri8 encodes an esterase responsible for deacetylation at C-3. This gene function was confirmed by cell-free enzyme assays and feeding experiments with yeast expressing Tri8. Previous studies have shown that Tri101 encodes a C-3 transacetylase that acts as a self-protection or resistance factor during biosynthesis and that the presence of a free C-3 hydroxyl group is a key component of Fusarium trichothecene phytotoxicity. Since Tri8 encodes the esterase that removes the C-3 protecting group, it may be considered a toxicity factor.

MeSH terms

  • Cell-Free System
  • Esterases / metabolism*
  • Fungal Proteins / metabolism*
  • Fusarium / enzymology*
  • Molecular Sequence Data
  • Saccharomyces cerevisiae / metabolism
  • Trichothecenes / metabolism*

Substances

  • Fungal Proteins
  • Trichothecenes
  • Esterases

Associated data

  • GENBANK/AF359361